Lifting and lowering mechanism



LIFTING AND LOWERTNG MECHANT. SM

Filed May 2' 1925 3 Sheets-Sheet l rToRNEv April 7, 1931. 1; c. DAWLEYLIFTING AND LOWRING MECHANISM ."5 sheets-sheet, 2

Filed May 2 erf l IN1/EN TOR. ,JAMES CTZ/wwf) 'ATTORNEY Api'il 7, 1931.AJ. C, DAWLEY l 1,799,581

LIFTING AND LOWEHING MECHANISM A TTORNEY Patented Apr. 7, 1931V Unir-E.STATES :Ai/ins. c. Viiniiri".nY,'

or DAYTON, OHIO, A CORPORATION-"Oromo LIFTING Ann 'LOWE-RING-ivrnoHnnIsM y Application filed May `2, 1925. Serial No. 27,386.

, This invention relates to lifting and lowering lmechanism 'and moreparticularly toa lifting jack of the pawl and ratchet type.

Olne object of the invention is to provide a pawl and ratchet ack withimprovedmeansy for automatically controlling the pawls to permit thelowering ofthe load under the control'of the operator. Y y

Afurther objectjof theinvention is to piovide such va jack which willbe*v simple in its construction, of a'strong durable characterk andwil-lhave no parts which will be readily broken or disarranged so as tointerfere with the Operation of the mechanism.

Other objects of the inventionwill appear as the mechanism `is describedin. detail.

In the accompanying drawings Fig. 1 is a vrear-elevation, partly brokenaway, of a jack embody-ing my invention-g Fig. 2 is a side elevation ofthe same, partlybroken away and showing the pawls in lifting positions;Fig. 3 is a side/elevation ofthe upper portion of the Ajack showing thepositions of the pawls at one stage of the lowering Operation; Fig. 4 isa similar view showing the positions of .the pawlsat a subsequent stageof the lowering operation; Fig. 5 is a section taken on the line 5-5 ofFig. 2; andV Fig. y6 is a section taken on the line 6-6 of Fig. '2.

In these ldrawings I have illustrated one embodiment of my inventionvand have shown the same as applied to a lifting jack the main featuresof construction `of which are well known but it will be understood thatthe 5 mechanism may take various forms and may beeinbodied' in liftingapparatuses of various kinds without departing from the spirit of theinvention. i

l lin that particular embodiment of theiiivolition here illustrated thejack comprises an upright standard 1 havingpat itslowe'r end aysupporting base 2 and ,having `mounted therein a vertical reciprocatorylifting element 3 which is provided in its rear edge with ratchet teeth1l. The upper end of this lifting element extends beyond. theupper end of the standard wherey it is provided with a work engaging. member or cap5 on which the load isrsupported. Pivotally mountedk in the rearlportion of thestandard l is a pawl carrier which is here shown ascomprising a hub portion' vof alever socket 7 which is carried orDAYTON, OHIO, assIGNon To TilinfJoYoE-ORIDLAND COMPANY,

by trunnions 8 `pivotally mounted inrvbearings -9 formed in the sidewalls of the stand- 'ard 1,the lever socket being adapted to rec eivefthel 'usual operating lever or bar. Mounted on the 4p'awl carrier orhub 6 of the lever socket is an actuating pawl 10 which is mounted formovement 'into 'and out of operative relationwith the teeth of thelifting element and which is so mounted on the pawl carrier thatthemovement ofthe lever socket about the axis of the trunnions 8 willimpart bodily niovcnient'to'the actuating paw-l iii the direction ofthelength of the` lifting ele- Inent. In'the present arrangement the pawlispivotally mounted in a recess yor socket formed in the forward *edgeof the hub of .the lever` socket, its axis being spacedl a sufficientdistance from the aX-is 'of the lever socket to permit vthe `desiredrange of moveV nient ofthe pawl.v Mounted within the standard 1, at apoint below the pawl carrier 6, is a second pawl carrierl which is hereshown as a sleeve or hub 11 mounted. on a shaft 12 which. is supportedYin the side walls o f the standard. Rigidly secured to this hub orsleeve k11 is a detent pawl y13 mounted-for movement about the axis ofthe shaft 12 into and out of operative relation to the teeth of thelifting element. Suitable spring means actsupon the detentv pawl 13 tocontrol the position thereof and means are provided for reversing theaction of this spring means so that when in one position it will tend toforce the detent pawl into operative engagement with the toothed liftingelement and when in another position itl will Aten/dpto rforce the pawlaway from the toothed lifting element. Preferably the hub oi' sleeve 11is provided Yce fig. uo

with a rearwardly extending arm 14 which carries at its rearend anapertured stud V15 which is pivotally mounted and through which extendsarod-16, the rod having slidingniovement in the apertui'ed stud. VThisrod is rio-idly Imounted at-its lower end in a supporting member yorcarrier 17 and is pro-A vided at its iipp'er'end4 with a head 18. Con`lined between the apertured stud` 15 and the head 18 `of the rod is aspring 19 which iS coiled about the rod. A similar spring 2O is coiledabout the rod between the apertured stud 15 and the supporting member17. The supporting member 17 is movably mounted and is so arranged thatwhen in one position the lower spring, 20, will be compressed and willact upon the arm 14 and thereby tend to force the detent pawl into anoperative position. When the supporting member is in another positionthe upper spring, 19, will be under compresion and will act on the arm14 in a direction to move the detent pawl into an inoperative position.lThis movement may be imparted to the supporting member in various waysbut, as here shown, it is pivotally mounted on a stud 21 which in turnis eccentrically mounted on the hub of an actuating lever 22 which ispivotally mounted on the standard 1, as shown at 23. The arrangement ofthe eccentrically mounted stud 21 is such that when the lever 22 is inthe po.- sition shown .in Figs. 1 and 2 the' supporting member will bein Van elevated position and the lower spring'20 will be undercompression, and when the actuating lever is in the position shown inFigs. 3 and 4 the supporting member will be in its lower position andthe upper spring 19 will be under compression.

Suitable means are provided for yieldably holding the actuating pawl 10in operative engagement withthe toothed lifting element but this mea-nsis of such a character and so controlled during the lowering operationthat it will tend to move the actuating pawl into an inoperativeposition. Preferably the action of this yieldable means on the actuatingpawl is controlled. by the lever 22 which controls the action of thespringmeans on the detent pa wl. To this end 1 have here shown thecontrolling means for the actuating pawl. as comprising an arm 24 whichis rigidly secured at its lower' end to a hub 25 which is mounted on theshaft 12 and which is provided with a rearwardly extending arm 26 havingpivotally mounted thereon an apertured stud 27 in which is slidablymounted a rod 28, this rod being rigidly mounted at its lower end in thesupporting member 17 and having at its upper end a head 29. Coiled aboutthe upper portion of the rod and confined between the head 29 and theapertured stud 27 is a spring 30 and coiled about the lower portion ofthe rod and confined between the apertured stud 27 and the supportingmember 17 is a second spring 31. rThe springs 30 and 31 are controlledby the movement of the supporting member 17 in the same manner as arethe springs 19 and 20. Consequently when the actuating lever 22 is inthe position shown in Figs. 1 and 2 the lower spring 31 will act uponthe arm 24 to move the same forwardly. This arm is so connected with theactuating pawl that this forward movement thereof will carry the pawlinto operative relation to the toothed lifting member. In the presentconstruction a pin and slot connection is established between the arm 24and the pawl 10, the arm having a longitudinal slot 32 into whichextends a pin 33 extending laterally from the pawl. lllhen the actuatinglever 22 is in the position shown in Figs. 3 and 4 the upper spring 30will be under compression and will tend to move the controlling arm 24in a rearward direction and thus carry' the actuating pawl into aninoperative position.

The sleeve or pawl carrier 11 for the detent pawl 13 is also providedwith a forwardly extending arm 34 on which is pivotally mounted anapertured stud 35 having slidably mounted therein a rod 3G, the upperend of which is rigidly secured to an arm 37 which is pivotally mountedat 38 on the hub or pawl carrier for the actuating pawl 10. Confinedbetween the arm 37 and the aperturcd stud 35 is a spring 39 which isstii'er or of greater strength than the springs 19 and 20, whichnormally control the position of the detent pawl. The arrangement of thespring 39 and its supporting means is such that when the springcontrolling means for the detent pawl is so positioned that it tends tomove that pawl into an inoperative position the downward movement of theactuating pawl and its carrier 6 will place the spring 39 undercompression and cause the same to act on the pawl carrier or hub 11 soas to move the detent pawl against the action of the spring 19 and intooperative relation to the toothed lifting element.

Then the actuating lever 22 is in the position shown in Figs. 1 and 2the several parts of the mechanism are in their lifting positions. Thesprings 20 and 31 are under compression and tend to hold the detentlpawl and the actuating pawl, respectively, in operative relation withthe toothed lifting element. As shown in Fig. 2 the lever socket is inits elevated position and it will be apparent that the downward movementof the lever will impart upward movement to the actuating pawl and tothe lifting element with which that pawl is in engagement and thatduring this upward movement the detent pawl will yield to permit theteeth of the lifting element to move past the same. `When the actuatinglever 22 is moved to the position shown in Figs. 3 and 4 the'severalparts of the mechanism are moved into their lowering positions, that is,positions in which they will `operate to permit the load to be loweredunder'the control of the operator by then'ianipulation of the leversocket 7. rlhe springs `19 and 3() are under compression and tend tomove the detent pawl and the actuating pawl'into their inoperativepositions. Vhen the lever socket 7 is in its lowermost position and theactuating pawl 10 in its elevated position, as shown in Fig. 4, the

load'wil'l be carried on the actuating pawl and the spring 19 will havemoved the detent pawl 13 into an inoperative position. The

action of the spring 30 on the actuating pawlwill tend to move that pawlout of engagement with the toothed lifting element but this movementwill be prevented by the tooth which overhangs the nose of the pawl andthereby prevents the pawl from moving about its a-Xis. Viith the partsin this positionfthe pressure on the lever socket A 7 is relieved sothat 'the weight of the load on the lifting element will move the samedownwardly. the lever socket moves upwardly the spring 39 will be placedunder compression and before the actuating pawl reaches the lower limitof its movement the tension of the spring'39 will become sufficient toovercome the action of the spring 19 and the detent pawl will be moved'into operative engagement with the teeth of the lifting element andrwill interrupt the movement of lthat lifting element and support theweight of'the'load thereon. The slight further downward movementimparted to the actuating pawl, by

the continued upward movement of the lever socket, will move the nose ofthe pawl:

out of contact with the overhanging tooth of the lifting element and,permit the pawl to be moved about its a-Xis by the action of the spring30 on the controlling armQl and the pawlwill be held in this inoperativeposition during the major portion of its upward movement,'which" isbrought about by the V downward movement of the lever socket.

During thisnpward movement of the pawl the Acompression ofthe spring 391s relieved but the detent pawl remainsin operative eni Vgagement withthe lifting elementfdue to the teeth overhangingthe nose of the pawl andpreventing its movement about its aXis. J ust before the actuating pawlreaches the upper limit of its movement it engages a yieldable member,such as la 'spring 10, which forces the same into engagement with thetoothed lifting element," against the action of the spring 30, and aslight further upward movement isimparted tothe actuating pawl toslightly elevate thek lifting element and thus release the detent pawl13 and permit the latterto be moved, by the spring 19 into aninoperative position, thus restoring the parts to the positions shown inFig. haften which the' cycle of operations above described is ref'peated" so tliatthe load will be loweredstep by step andiwill be at alltimes under the direetcontrol of the operator. A

I have also provided means for moving the detent Vpawl into aninoperative position independently of the controlling r mechanism aboveYdescribed, when it is desired to release the' liftingeleme'nt and allowit to run down quickly, without control. YAs here shown, this meanscomprises a flexible member, such as a chai'nal, connected withtl'i'epawl 1S and extlendingto a point outside the hollow standarc j 1 tf Whilel have shown and 'described one `embodiment of my invention 'Iwish it to be understood that I do not'desire to `be limited tcv thedetails thereof as various modifications may' occurl to a person skilledin the art.Y

Havingnowfully described my invention what 'claim' as new and desire tosecureby Letters-Patent, is: l

" 1; In ya vlifting apparatus, a standard, ay toothed lifting elementmounted. on` said standard,"an actuating pawl for said lifting'element', means to impart operative movement to said pawl, a detent pawlmounted for movement into and out of operative relation to said liftingelement, yieldable means acting on said detent pawl to hold it inaninoperative position during the downward movement of said liftingelement, and a controlling device mounted for movement with relation toand acting on said detent' pawl during'said downward movement. of saidlifting element to move the same agaist the action of said yieldablevmeans and into operative relation to said lifting element.

'2. In a lifting apparatus, a standarda toothed lifting element Vmountedon saidl standard, an actuating pawl for said lifting element, means toimpart operative movement to said pawl, a'detentipawl/ mounted forfmovement into and outof operative relation to-said lifting element,yieldable means act-- ing on said detent pawlptohold it in aninoperative position during the downwardmovement of said liftingelement, and" a device mounted for movement with relation to andarranged' to be operated by the operating means for Asaid actuatingpawl. for moving movement of said liftingv element, an opern able deviceinterposed between said detent pawl and the operating means forfsaidactuating pawl and arranged to' be actuatedby ward movement of saidlifting element to move said detent pawl against theactiony of saidyieldablemeans and into operativefrelation with said lifting element,and means for automatically moving said actuating. pawl into aninoperative position after said detent pawl' has beenmoved into anvopera"- tiveposit-ion.

said operating means duringl thev downles 4. In a lifting apparatus, astandard, a toothed lifting element mounted on said standard, anactuating pawl for said lifting element, means to impart operativemovement to said pawl, a detent pawl mounted for movement into and outof operative relation to said lifting element, yieldable means acting onsaid detent pawl to hold it in an inoperative` position during thedownward movement of said lifting element, an operable device interposedbetween and connected with said detent pawl and the operating means forsaid actuating pawl and acting on said detent pawl during the downwardmovement of said lifting element to move said detent pawl against theaction of said yieldable means and into operative relation to saidlifting element, and means for automatically moving said actuating pawlinto an inoperative position after said detent pawl has been moved intoan operative position, for holding said actuating pawl in saidinoperative position during the major portion of its upward movement andfor moving the sameA into an operative position just before it completesits upward movement.

5. In a lifting apparatus, a standard, a toothed lifting element mountedon said standard, an actuating pawl for said lifting element, means toimpart operative movement to said pawl, a detent pawl mounted formovement into and out of operative relation with said lifting element,yieldable means acting on said pawls to hold the same normally inoperative relation with said lifting element, means for reversing theaction of said yieldable means, whereby it will tend to move both ofsaid pawls into inoperative positions, and an operable device interposedbetween and connected with said detent aawl and the operating means forsaid actuating pawl and controlled by the downward movement of saidactuating pawl when said yieldable means ,is in its reverse position tomove said detent pawl against the action of said yieldable means andinto operative relation with said lifting element just before saidactuating pawl completes its downward movement. n

6. In a lifting apparatus, a standard, a toothed lifting element mountedon said standard, an actuating pawl for said lifting element, means toimpart operative movement to said actuating pawl, a detent pawl mountedfor movement into and out of operative relation'to said lifting element,spring means acting on said detent pawl to hold the same in aninoperative position during the downward movement of said actuatingpawl, a second spring arranged to act on said detent pawl .to move thesame toward its operative position against the action of the firstmentioned spring means,.and means controlled by the downward movement ofsaid actuating pawl to render the last mentioned spring opera# tive.

7. In av lifting apparatus, a standard, a toothed lifting elementmounted on said standard, an actuating pawl for said lifting element, acarrier for said pawl, means for actuating said carrier to impart bodilymovement to said pawl, a detent pawl, spring means acting on said detentpawl to hold the same out of engagement with the teeth of said liftingelement during the downward movement of said actuating pawl, and adevice connected with said detent pawl and actuated by the carrier forsaid actuating pawl to move said detent pawl against the action of saidspring means and into engagement with said toothed lifting element justbefore said actuating pawl reaches the lower limit of its movement.

8. In a lifting appara-tus, a standard, a toothed lifting elementmounted on said standard, an actuating pawl for said lifting element,means to impart operative movement to said actuating pawl, a detent pawlmounted for movement into and out of operative engagement with saidlifting element and comprising a hub, an arm rigidly secured to saidhub, a rod extending transversely to and slidably connected with saidarm, springs carried by said rod and arranged on the opposite sides ofsaid arm, whereby one or the other of said springs will be undercompression according to the position of said rod with relation to saidarm, means for controlling the position of said rod, a second armconnected with said hub, a rod extending transversely to said second armand movable relatively thereto, a spring carried by said last mentionedrod and arranged to act on the last mentioned arm to move said detentpawl against the action of one of the first mentioned springs, and meanscontrolled by the movement of said actuating pawl to place the lastmentioned spring under compression.

9. In a lifting apparatus, a standard, a toothed lifting element mountedon said standard, an actuating pawl for said lifting element, a pawlcarrier on which said pawl is pivotally mounted, means for actuatingsaid pawl carrier, a detent pawl pivotally mounted for movement towardand from'said toothed lifting element and comprising a hub, an armrigidly secured to said hub and extending from that side thereofopposite said lifting element, a pivoted stud carried by said arm, a rodslidably mounted in said stud and having a head at its upper end, asupporting member rigidly secured to the lower end of said rod, springsconfined between said stud and said head and between said stud support'-lng member, means for adjusting said supporting member with relation tosaid arm to place one or the other of said springs under compression, asecond arm rigidly secured to the hub of said detent Vpawl, andextending from-thatside of saidnhub opposite theiirst lmentioned arm, anyapertured stud pivotally mountedin thelastmentioned arma .rod slidablymounted in kthe last mentioned apertured-stud, a connection between thelast mentioned rodand the carrier for said actuating lpawl, and a springmounted on said last-inen- Vtioned ro'd between the apertured stud `andsaidpawlncarrier and arranged to be placed under kcompression Vwhen saidvpawl .carrier .movesiin a .direction tolower saidactuating awl. v ll0'. VIn a lifting apparatus, .a standard, a' toothed lifting elementVmounted on said standard, anv actuating pawl for saidlifting element,means to impart vertical movement to said pawl, `yieldable means actingon said pawl to-move the saine into an operative `poaction of the lastmentioned yieldable means v awl to move said detent pawlagainstthe andinto operative engagement with said lifting element just ybefore saidactuating pawl completes its downward movement, thereby causing thefurther movement of said actuating pawl to release the same from saidlifting element and permit it to be moved into an inoperative positionby the first mentioned yieldable means. f

11. In a lifting apparatus, alstandard, al toothed element mounted onsaid standard, an actuating Vpawl for said lifting element, means toimpart vertical movement to said actuating pawl, a yieldable devicetending to move said pawl out of engagement withy said lifting element,such movement being resisted by the contact between said pawl and atooth of said lifting element, a detent pawl, a spring acting on saiddetent pawlto hold the same out of engagement with said' lift,- ingelement during the downward movement of said actuating pawl and saidlifting element, a normally inoperative yspring arranged to act on saiddetent pawlto move the same against the action of the first mentionedspring .and into engagement with said lifting element, and meanscontrolled by the downward movement of said actuating pawl to place thelast mentioned spring under compression andvthereby cause said detentpawl to engage said lifting element before said actuating pawl hascompleted its downward movement, wherebythe further move- Iment of saidactuating pawl will releaseV the same from said lifting element andpermit it to be moved into an inoperative position by said yieldablemeans.

l2. In a lifting-apparatus, a: standard, a

toothed lifting element mounted on saidv standard, an actuatingpawl forsaid lifting tending to move vsaid pawlout ofengagement with'saidliftingelement, such `movement'being resisted bythe contactbetweensaid pawl anda tooth of said lifting element, af'detent v pawl, a springacting on said `detent pawl to hold the same .out -of engagement withsaid 'lifting element during the downward movev.mentof said l.actuatingpawl and saidV lifting '.elemeiit, a normally inopera'tivefspring ariranged to act on said detentpawl'to move the same a gainst'th-e actionofthe iirst mentioned spring and into engagement with said liftingelement, means controlled by the downward' movement ofsaid .actuatingpawl to place jthellastmentioned spring under compression n and therebycause said detent pawlto engage said Vlifting element before saidactuating pawlhas completedfits.downward movement, whereby .the further.movement of said actuating jpawl willrelease the sameffrom said liftingelement and permit it to be moved into an inoperative .position by saidyieldable means, and means to act .oni said actuating pawl asthe ,latterapproaches-the upper limit of its mOVementandfOrce the sameintoenyieldable device. l v

A 13. jIn; a liftin'gapparatus, a standard,.a toothed lifting elementmounted .on said standard, an actuatingpawl'for said`.lii'.t`ingelement, means to impart 'vertical .bodily .movement to said vactuatingpawl, -yieldable vmeansactingon saidpawlto force the same away'fromsaid'lifting element, a detent pawl,

Va spring .acting onsaiddetent pawl vtohold :the saineoutofengagement-with said lifting element duringthef downward ,movement ofsaid actuating ,pawlasecondspring con'- neeted with said detent.pawhan'd means con trolled by the downward.movement .of 'said actuatinglpawl to.l place .said-A second spring;Y runder `rcompression and cause.the same .to

.move s'aid'detentpawl against the actionof Vthe first mentioned sui-ingandinto engagement 'with said liftingelement.

i: .l/.In a lifting apparatus, astandard, -a

toothedliftingelement .mountedon said standard,.an actuatingV pawl y.forsaid .lifting element, means tofimpart operative move-l jment to `saidactuatingpawl, a detentpawl,

yieldable means for holding both pawlsin operativerelation ,withsaid`lifting ,y element ydni-ing vthe lifting operation, .means to reversetheactionof said Y'yieldable meanslon said pawls, whereby-said yieldablemeans Y, Ywill-.tendto movefbothvpawlsjinto inoperative Y positionswith. relation n vto y,said lifting ele- Vnient during thefloweringoperatiomsaid ac` 'tuating :pawl being held in,v engagementl with saidlifting element during the downward movement thereof by its contact withthe tooth of said lifting element, a spring connected with said detentpawl and arranged to be placed under compression by the downwardmovement of said actuating pawl, the strength of said spring beinggreater than the strength of the yieldable means which tends to holdsaid pawl in an inoperative position, whereby said detent pawl will beVmoved against the action of said yieldable means and into engagementwith said lifting element.

l5. In a lifting apparatus, a standard, a toothed lifting elementmounted on said standard, an actuating pawl for said lifting element, apawl carrier on which said actuating p'awl is pivotally mounted, meansfor actuating said pawl carrier to impart bodily movement to saidactuating pawl, a controlling arm pivotally mounted on said standard andoperatively connected with said actuating pawl to move the same towardor from said lifting element, a second arm rigidly connected with andextending transversely to said controlling arm, a rod slidably connectedwith the last mentioned arm and having a head at one end thereof, anadjustable supporting member rigidly secured to the other end of saidrod, springs confined between said last mentioned arm, said head Vandsaid supportingmember, respectively, a detent pawl mounted for movementinto and out of engagement withsaid lifting element and comprising ahub, an arm rigidly securedV to said hub, a rod slidably mounted undercompression when said actuatingV pawl is moved downwardly.

16. In a lifting apparatus, a standard, a toothed lifting elementmounted on said standard, an actuating pawl for said lifting element,means to impart vertical bodily movement to said actuating pawl, apivoted controlling member operatively connected witlisaid pawl, aspring acting on said controlling member and tending to move the sameabout its aXis and to force said pawl away vfrom said lifting element, adetent pawl mounted for movement into and out of operative relation withsaid lifting element, yieldable means acting on said detent pawl to holdit in an inoperative position during f theldownward'movement of saidlifting element, andineans acting on said detent pawl during thedownward movement of said lifting element to move the same against theaction of said yieldable means and into operative relation with saidlifting element.

17. In a lifting apparatus, a standard, a toothed lifting elementmounted on said standard, an actuating pawl for 'said element, a pivotedarm having a slot near its free end, a pin carried by said pawl andhaving sliding movement in said slot, a spring acting on said arm in adirection to force said pawl away from said lifting element, a detentpawl mounted for movement into and out of operative relation with saidlifting element, yieldable means acting on said detent pawl to hold itin an inoperative position during the downward movement of said liftingelement, and means acting on said detent pawl during the downwardmovement of said lifting element to move the same against the action ofsaid yieldable means and into operative relation with said liftingelement.

In testimony whereof, I aiiix my signature hereto.

JAMES C. DAWLEY.

